ref: fa095decfa65ce7fa2d03ad6fb1d75640c0803b1
dir: /tests/cc/execute/0154-if_defined.c/
#if defined(FOO)
int a;
#elif !defined(FOO) && defined(BAR)
int b;
#elif !defined(FOO) && !defined(BAR)
int c;
#else
int d;
#endif
int
main(void)
{
return c;
}